1,213 research outputs found

    Design, construction, and operation of an unmanned underwater vehicle

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaf [62]).The practical usage of unmanned underwater vehicles (UUVs) is limited by vehicle and operation cost, difficulty in accurate navigation, and communication between the vehicle and operator. The "Rex 2" UUV employs a system design where a submersible is connected to a float at the water's surface by means of a tether. By maintaining a surface expression, high-bandwidth radio communication to the operator becomes possible, and GPS may be used for accurate navigation. This arrangement allows the freedom of movement characteristic of untethered autonomous underwater vehicles (AUVs), while maintaining the live operator control and communication found with tethered remotely operated vehicles (ROVs). Expanding on the design and field experiences with the MIT AUV Lab's first Reef Explorer UUV, Rex 2 was designed to be inexpensive, easy to deploy, adaptable to various payloads, and simple to use. Rex 2 was designed, built, and operated in a number of ocean field tests, validating the utility of the vehicle and system concept.by Dylan Owens.S.M

    Ultrasound Guided Robot for Human Liver Biopsy using High Intensity Focused Ultrasound for Hemostasis

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    Percutaneous liver biopsy is the gold standard among clinician\u27s tool to diagnose and guide subsequent therapy for liver disease. Ultrasound image guidance is being increasingly used to reduce associated procedural risks but post–biopsy complications still persist. The major and most common complication is hemorrhage, which is highly unpredictable and may sometimes lead to death. Though the risk of mortality is low, it is too high for a diagnostic procedure. Post-biopsy care and additional surgical intervention to arrest hemorrhage make liver biopsy a costly procedure for health care delivery systems. Non-invasive methods to stop bleeding exist like electro–cautery, microwave, lasers, radio frequency, argon–beam, and High Intensity Focused Ultrasound (HIFU). All the methods except HIFU require direct exposure of the needle puncture site for hemostasis. HIFU is an ultrasound modality and uses mechanical sound waves for focused energy delivery. Ultrasound waves are minimally affected by tissue attenuation and focus internal targets without direct exposure. Human error in focusing HIFU renders it unusable for a medical procedure especially when noninvasive. In this project we designed and developed an ultrasound guided prototype robot for accurate HIFU targeting to induce hemostasis. The robotic system performs percutaneous needle biopsy and a 7.5 cm focal length HIFU is fired at the puncture point when the needle tip retracts to the liver surface after sample collection. The robot has 4 degrees of freedom (DOF) for biopsy needle insertion, HIFU positioning, needle angle alignment and US probe image plane orientation. As the needle puncture point is always in the needle path, mechanically constraining the HIFU to focus on the needle reduced the required functionality significantly. Two mini c-arms are designed for needle angle alignment and US probe image plane orientation. This reduced the contact foot print of the robot over the patient providing a greater dexterity for positioning the robot. The robot is validated for HIFU hemostasis by a series of experiments on chicken breasts. HIFU initiated hemorrhage control with robotic biopsy ensures arrest of post-biopsy hemorrhage and decreases patient anxiety, hospital stay, morbidity, time of procedure, and cost. This can also be extended to other organs like kidneys, lungs etc. and has widespread implications such as control of hemorrhage in post-biopsies in patients with reduced ability for hemostasis. This research opens a greater scope for research for automation and design making it a physician friendly tool for eventual clinical use

    Musical Gesture through the Human Computer Interface: An Investigation using Information Theory

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    This study applies information theory to investigate human ability to communicate using continuous control sensors with a particular focus on informing the design of digital musical instruments. There is an active practice of building and evaluating such instruments, for instance, in the New Interfaces for Musical Expression (NIME) conference community. The fidelity of the instruments can depend on the included sensors, and although much anecdotal evidence and craft experience informs the use of these sensors, relatively little is known about the ability of humans to control them accurately. This dissertation addresses this issue and related concerns, including continuous control performance in increasing degrees-of-freedom, pursuit tracking in comparison with pointing, and the estimations of musical interface designers and researchers of human performance with continuous control sensors. The methodology used models the human-computer system as an information channel while applying concepts from information theory to performance data collected in studies of human subjects using sensing devices. These studies not only add to knowledge about human abilities, but they also inform on issues in musical mappings, ergonomics, and usability

    Human Machine Interfaces for Teleoperators and Virtual Environments

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    In Mar. 1990, a meeting organized around the general theme of teleoperation research into virtual environment display technology was conducted. This is a collection of conference-related fragments that will give a glimpse of the potential of the following fields and how they interplay: sensorimotor performance; human-machine interfaces; teleoperation; virtual environments; performance measurement and evaluation methods; and design principles and predictive models

    Apparatus for providing sensory substitution of force feedback

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    A feedback apparatus for an operator to control an effector that is remote from the operator to interact with a remote environment has a local input device to be manipulated by the operator. Sensors in the effector's environment are capable of sensing the amplitude of forces arising between the effector and its environment, the direction of application of such forces, or both amplitude and direction. A feedback signal corresponding to such a component of the force, is generated and transmitted to the environment of the operator. The signal is transduced into an auditory sensory substitution signal to which the operator is sensitive. Sound production apparatus present the auditory signal to the operator. The full range of the force amplitude may be represented by a single, audio speaker. Auditory display elements may be stereo headphones or free standing audio speakers, numbering from one to many more than two. The location of the application of the force may also be specified by the location of audio speakers that generate signals corresponding to specific forces. Alternatively, the location may be specified by the frequency of an audio signal, or by the apparent location of an audio signal, as simulated by a combination of signals originating at different locations

    Sensory Communication

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    Contains table of contents for Section 2, an introduction and reports on fourteen research projects.National Institutes of Health Grant RO1 DC00117National Institutes of Health Grant RO1 DC02032National Institutes of Health/National Institute on Deafness and Other Communication Disorders Grant R01 DC00126National Institutes of Health Grant R01 DC00270National Institutes of Health Contract N01 DC52107U.S. Navy - Office of Naval Research/Naval Air Warfare Center Contract N61339-95-K-0014U.S. Navy - Office of Naval Research/Naval Air Warfare Center Contract N61339-96-K-0003U.S. Navy - Office of Naval Research Grant N00014-96-1-0379U.S. Air Force - Office of Scientific Research Grant F49620-95-1-0176U.S. Air Force - Office of Scientific Research Grant F49620-96-1-0202U.S. Navy - Office of Naval Research Subcontract 40167U.S. Navy - Office of Naval Research/Naval Air Warfare Center Contract N61339-96-K-0002National Institutes of Health Grant R01-NS33778U.S. Navy - Office of Naval Research Grant N00014-92-J-184

    The Middlesex University rehabilitation robot

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    This paper outlines the historical developments of Wheelchair-Mounted Robot Arms (WMRA's) and then focuses on the ongoing research at Middlesex to develop a low-cost aid to daily living for users with high-level quadriplegia. A detailed review is given explaining the design specification. It describes the construction of the robotic device and its control architecture. The prototype robot used several gesture recognition and other input systems. The prototype has been tested on disabled and non-disabled users with positive feedback. They observed that it was easy to use, but issues about speed of operation were resolved after further development. The robot has a payload of greater than 1kg with a maximum reach of 0.7–0.9m. Published by the Taylor & Francis Publishing Group, this publication is one of the only journals to cover the multi-disciplinary area of medical technology research. Currently, research bids are being formulated with the School of Computing Science to continue this research
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